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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

22062 results found.

  1. GRB 021004: Additional V-band Polarimetric Observations
  2. GRB 021004 submm observations
  3. GRB021004: NIR and Optical observations
  4. GRB 021004: Optical observations, AUDE network
  5. GRB 021004 - VLA Radio Observations
  6. GRB 021004 - Unusual Radio-to-Submm Spectrum
  7. GRB 021004: optical spectroscopy
  8. GRB 021004: HST/STIS spectroscopic observations
  9. GRB021004: optical observations and predicted break time
  10. GRB021004: BVRc photometry
  11. GRB 021004 continued IR fading
  12. GRB 021004, spectroscopic observations
  13. GRB 021004: polarimetric observations
  14. GRB 021004: V-band Polarimetric Observations
  15. GRB021004: Update Bisei photometric data
  16. GRB021004, Optical Observations
  17. GRB 021004: Optical observations at RIKEN
  18. GRB 021004: Optical Observations
  19. GRB 021004: Optical Photometry at 1.5 Days
  20. GRB021004, Optical Observations
  21. GRB 021004: Optical observations
  22. GRB 021004, optical observations
  23. GRB021004: Optical Spectroscopy
  24. GRB 021004: Optical Observations
  25. GRB 021004, SPM optical observations
  26. GRB 021004, optical observations
  27. GRB 021004: radio observations
  28. GRB 021004: steepening of the optical decay slope
  29. GRB021004: Upper limits from recent and historical observations
  30. GRB021004: optical observations at Nyrola
  31. GRB021004: optical observations at Bisei
  32. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  33. GRB021004: Optical Afterglow
  34. XRF020903: TNG and Asiago photometry
  35. GRB 020903: Optical observations at RIKEN
  36. XRF 020903: Correction to GCN 1560
  37. XRF 020903: VRI observations
  38. GRB 020903: correction to GCN 1557
  39. XRF 020903: R band observations
  40. XRF 020903: Archival Optical Images
  41. Radio Observations of XRF 020903: The Missing Link
  42. XRF 020903: Supernova
  43. GRB 020305: HST/STIS observations
  44. GRB020322 : HST/STIS observations
  45. XRF 020903: Optical observations
  46. XRF 020903: Optical observations
  47. XRF 020903, optical observations
  48. GRB020813: High-resolution optical spectroscopy
  49. GRB020819: optical observations at Bisei
  50. GRB020812: negative optical observations
  51. Second epoch K band imaging of GRB 020819
  52. GRB 020813 : HST observations
  53. Confirming no variability for GRB02081
  54. GRB020819 : Optical observations at KISO
  55. GRB 020819: Optical observations
  56. K band observation of GRB 020819
  57. GRB020819: optical observations
  58. HETE 2275: Optical observations
  59. GRB020813: optical and NIR observations
  60. GRB020813: Fading X-ray Afterglow Observed with Chandra
  61. GRB020813: optical observations at Bisei
  62. GRB020812: NIR observations
  63. Polarimetry of GRB020813: evidence for variability
  64. GRB020813 IRAM millimeter observations
  65. GRB020812: optical observations
  66. GRB020813: High-Resolution Optical Observations
  67. GRB 020812: optical observation at Bisei
  68. GRB020813: optical observations; possible host galaxy
  69. GRB 020813, radio detection
  70. GRB 020812 : optical afterglow candidate
  71. GRB020813, optical observations
  72. Millimeter observation of GRB 020813
  73. GRB020812: optical observations
  74. GRB 020813 : KISO multiband optical observations
  75. GRB020813, optical observations
  76. GRB 020813 Afterglow Observations; Possible break
  77. GRB 020813 multiband optical observations
  78. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  79. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  80. GRB 020715, optical observations
  81. GRB 020714, optical observations
  82. GRB020801: Candidate OT present in DSS
  83. HST Imaging of the Host of GRB 011121
  84. GRB020331: Late-time Optical Light Curve (re-submission)
  85. GRB020331: Late-time Optical Light Curve
  86. GRB 020405: HST observations reveal red bump
  87. GRB 020410: Discovery of Probable OT by HST
  88. GRB 020124, HST observations of the fading afterglow
  89. GRB 020705: Optical observations
  90. GRB 020625, optical observations
  91. GRB 020625: Optical observations
  92. GRB 020531: optical photometry of Chandra sources
  93. HETE #2081: Optical observations
  94. The Probable Host Galaxy of GRB/XRF 020427
  95. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  96. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  97. AXP 1E2259+586 optical observations
  98. Fading Optical Source in the Field of GRB020531
  99. GRB 020531, INT+WFC deep optical upper limits
  100. SGR-like Bursts from the AXP 1E 2259+586

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